Bit guide



March 2, 1937. y Q E, THOMAS V 2,072,320

original 'Filed Dec. 19, 1934 Patented Mar. .11937 UNITED. srxlAI-:S`

rArENr omer.

- Brr GUIDE Charles E. Thomas, Santa Barbara, Calif.

.Application December 19,1'934, serial No. 158.2611

I Renewed July 7, 1936v terdhave tendency todeviate the bit, fromv a truly vertical course-resulting in the dilling of crooked holes. A,

An object of the present invention is to provide a bit'guide for rotary drill stems f'such designI as to eectively guide the bit during vits rotation and maintain it upon a 'course more nearly approaching the vertical. l

vA further object of `the invention is to provide' a bit guide which is normally .rotatable relatively to'the drill pipe, enablihg`-the drill stem to be l rotated relatively to the guide and'to provide an anti-friction bearing'between the guide 'and the* stem. inasmuch asthe guide remains stationary in the well during a major portion of the drilling` operations, opportunity is-present forthe bit guid to become stuck'in the 'well.hole. `.It is' a n further object of the invention to provide means f' V- for locking the guide with respect to the drill stem so that in the event that the 'guide should become stuck it niay be rotated by the drill, stem and thus freed, enabling recovery. e

With the foregoing and other objects in view, which will be made' manifest in v'the following detailed description,'a,nd specifically pointed out in the appended claims, reference is had to the accompanying bodment of the invention, wherein:

- 35,- Fig. 1 is a verticalsection through a well, illustrating the improve guidein position therein.A

section through the im`l Fig. 2 is a vertical proved bit'vguideey i Fig 3 is a horizontal section taken substantially upon' the lline M upon Fig. 2.

Referring .to the accompanying drawing characters designate similar parts "throughoiit, vvIll designates awell wherein lsimilar reference hole that is being drilled by abit II which is rotated bymeans of a drill stem or drill pipe I2. The bit guide consists ofa special section of drill pipe I3; provided .with a threaded pin and blocks.

incorporated in the drill pipe enabling it to be A"at 4a point near bit II.. Section I3has topand bottom' shoulders' Il and I 5, respectively, 4between which isv disposed the bodyf the bit guide proper.

i This birguiaebedy. ildieated et le'mey be formed'oi two parts'se ured togethenabout section' I3 or section I3 maybe made of two parts.

5.5L connected as by threads I 1,.as` shown, -to enable the shoulders.

` minimum amount of drawing Afor an illustrative ern-. l

vfriction bearings 2l and 23. The bit I I is kept on the body of the guide to be slipped on between The body has a plurality of radially extending teeth I8 dening passages or flutesu I9 therebetween which' provide forV the upward ilow 'of' circulation .iiuid that is discharged 5 through the ports in bitl II.` The outer ends of the teeth arearranged on a. circle substantially equal to the diameter of.. the -hole drilled by bit Il. The top of the body I6 is recessed as at 20 to receive an anti-frictionbearlng 2|, which may l0 be of any preferred design; thus forming ananti friction bearing between the drill stem' and the body at the top of'the'guide. The bottom of the body 4IIS has a deep recess 22 w ch` receives a similar anti-friction bearing 23. ABeneath this 16 anti-friction beartiisg'there is. disposed a thrust bearing 24 andi; in turn, is supported 'on a spring '25 which issupported on shoulder I6. Spring 25 is, of .suillcient strength' to support the bit guide body II.l notches or recesses 26 adapted to receive projec tions 21 on the bottom of the body, I6. These projections and recesses cooperate to forma typeA of clutch between the drill-stem andthe'body I6. The clutch is 'normal held out of engagement 25 by means of spring 25 supporting thebody in elevated position.

x The operation and advantages'of the improved bit. guide are as follows: i

During norma drilling operations tneieeui le' so..

engage the well walls, holding the body I6 stationary. The drill stem rotates Withinit with a friction due to the antia straight. vertical course by the steadylng eiIect 35 .aflordedfby the body.\ As' drilling progresses.'-

I "the eventthat the bit wears' out of gauge the knife-like edges on teeth I8 are such as Vto permit 40 the body to be readily forced downwardly in the e,

well regardless of the fact that the hole drilled may be slightly smaller than the bit guide body.

-Inasmuch as the bit guidebody 'remains stai tionary and affords a typeo steadying bearing 45 for the drill stem, there maybe occasion for the4 A bo'dy to become stuck. It such is the case, when it is' desired to replace bit 4II with a sharp bit.

an upward strain can be taken upon the' drill pipe compressing spring25. This 'enables the clutch 50 formedby projections 21 and recesses 26 to engage and enables the'bit guide body to be rotated "by means of the drill pipe. lThis rotation of the Y body :enables itV to be'freed inthe well', whereas a .5J I mere upward strain without the application of Onfshoulder I5 there are cut 20' rotating torque might not be suilicient to remove the guide. Y

AIt will be noted that the improved guide forms a relatively long bearing immediately behind the bit.so that regardless of the limberness of the drill pipe the bit will be maintained on a straight course regardless of formation dips. If desired, an additional guide may be located higher on the drill stem for increased steadying effect. A

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as deiined by the appended claims. l

I claim:

1. In combination with a drill stem, a bit guide jsurrounding the drill sternv having teeth vengageable with the walls of a. well and defining passages therebetween enabling upward ow of circulation uid, means forming a clutch between the guide 20 and the drill stem, and spring means normally holding the clutch disengaged 2. In combination with a drill stem having a bit thereon, a bit guide surrounding the drill stem near the blt and rotatable relatively thereto, there being teeth nearthe guide engageablewith the formation and dening passages enabling the upward flow o1' circulation fluid, anti-friction bearings between the guide and the drill stem at the top and bottom of the guide, means forming a clutch between the bottom of the guide and the drill stem, and spring means normally holding l the clutch disengaged.

3. In combination with a drill stem, a bit guide surrounding the drill stem having spaced portions engageable with the walls of a well and providing passages therebetween' enabling upward flow -oi' circulation duid, said bit guide being mounted for rotation on'the drill stem so that the drill stem may rotate therein, and means forming a normally disengaged clutch between the guide and the drill stem enabling the guide to be rotated by the drill stem when it is desired to remove it CHARLES E. THOMAS. 

